/*-------------------------------------------------------------------------
 *
 * ginvalidate.c
 *      Opclass validator for GIN.
 *
 * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * IDENTIFICATION
 *            src/backend/access/gin/ginvalidate.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"

#include "access/amvalidate.h"
#include "access/gin_private.h"
#include "access/htup_details.h"
#include "catalog/pg_amop.h"
#include "catalog/pg_amproc.h"
#include "catalog/pg_opclass.h"
#include "catalog/pg_opfamily.h"
#include "catalog/pg_type.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
#include "utils/syscache.h"
#include "utils/regproc.h"


/*
 * Validator for a GIN opclass.
 */
bool
ginvalidate(Oid opclassoid)
{// #lizard forgives
    bool        result = true;
    HeapTuple    classtup;
    Form_pg_opclass classform;
    Oid            opfamilyoid;
    Oid            opcintype;
    Oid            opckeytype;
    char       *opclassname;
    HeapTuple    familytup;
    Form_pg_opfamily familyform;
    char       *opfamilyname;
    CatCList   *proclist,
               *oprlist;
    List       *grouplist;
    OpFamilyOpFuncGroup *opclassgroup;
    int            i;
    ListCell   *lc;

    /* Fetch opclass information */
    classtup = SearchSysCache1(CLAOID, ObjectIdGetDatum(opclassoid));
    if (!HeapTupleIsValid(classtup))
        elog(ERROR, "cache lookup failed for operator class %u", opclassoid);
    classform = (Form_pg_opclass) GETSTRUCT(classtup);

    opfamilyoid = classform->opcfamily;
    opcintype = classform->opcintype;
    opckeytype = classform->opckeytype;
    if (!OidIsValid(opckeytype))
        opckeytype = opcintype;
    opclassname = NameStr(classform->opcname);

    /* Fetch opfamily information */
    familytup = SearchSysCache1(OPFAMILYOID, ObjectIdGetDatum(opfamilyoid));
    if (!HeapTupleIsValid(familytup))
        elog(ERROR, "cache lookup failed for operator family %u", opfamilyoid);
    familyform = (Form_pg_opfamily) GETSTRUCT(familytup);

    opfamilyname = NameStr(familyform->opfname);

    /* Fetch all operators and support functions of the opfamily */
    oprlist = SearchSysCacheList1(AMOPSTRATEGY, ObjectIdGetDatum(opfamilyoid));
    proclist = SearchSysCacheList1(AMPROCNUM, ObjectIdGetDatum(opfamilyoid));

    /* Check individual support functions */
    for (i = 0; i < proclist->n_members; i++)
    {
        HeapTuple    proctup = &proclist->members[i]->tuple;
        Form_pg_amproc procform = (Form_pg_amproc) GETSTRUCT(proctup);
        bool        ok;

        /*
         * All GIN support functions should be registered with matching
         * left/right types
         */
        if (procform->amproclefttype != procform->amprocrighttype)
        {
            ereport(INFO,
                    (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                     errmsg("operator family \"%s\" of access method %s contains support procedure %s with different left and right input types",
                            opfamilyname, "gin",
                            format_procedure(procform->amproc))));
            result = false;
        }

        /*
         * We can't check signatures except within the specific opclass, since
         * we need to know the associated opckeytype in many cases.
         */
        if (procform->amproclefttype != opcintype)
            continue;

        /* Check procedure numbers and function signatures */
        switch (procform->amprocnum)
        {
            case GIN_COMPARE_PROC:
                ok = check_amproc_signature(procform->amproc, INT4OID, false,
                                            2, 2, opckeytype, opckeytype);
                break;
            case GIN_EXTRACTVALUE_PROC:
                /* Some opclasses omit nullFlags */
                ok = check_amproc_signature(procform->amproc, INTERNALOID, false,
                                            2, 3, opcintype, INTERNALOID,
                                            INTERNALOID);
                break;
            case GIN_EXTRACTQUERY_PROC:
                /* Some opclasses omit nullFlags and searchMode */
                ok = check_amproc_signature(procform->amproc, INTERNALOID, false,
                                            5, 7, opcintype, INTERNALOID,
                                            INT2OID, INTERNALOID, INTERNALOID,
                                            INTERNALOID, INTERNALOID);
                break;
            case GIN_CONSISTENT_PROC:
                /* Some opclasses omit queryKeys and nullFlags */
                ok = check_amproc_signature(procform->amproc, BOOLOID, false,
                                            6, 8, INTERNALOID, INT2OID,
                                            opcintype, INT4OID,
                                            INTERNALOID, INTERNALOID,
                                            INTERNALOID, INTERNALOID);
                break;
            case GIN_COMPARE_PARTIAL_PROC:
                ok = check_amproc_signature(procform->amproc, INT4OID, false,
                                            4, 4, opckeytype, opckeytype,
                                            INT2OID, INTERNALOID);
                break;
            case GIN_TRICONSISTENT_PROC:
                ok = check_amproc_signature(procform->amproc, CHAROID, false,
                                            7, 7, INTERNALOID, INT2OID,
                                            opcintype, INT4OID,
                                            INTERNALOID, INTERNALOID,
                                            INTERNALOID);
                break;
            default:
                ereport(INFO,
                        (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                         errmsg("operator family \"%s\" of access method %s contains function %s with invalid support number %d",
                                opfamilyname, "gin",
                                format_procedure(procform->amproc),
                                procform->amprocnum)));
                result = false;
                continue;        /* don't want additional message */
        }

        if (!ok)
        {
            ereport(INFO,
                    (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                     errmsg("operator family \"%s\" of access method %s contains function %s with wrong signature for support number %d",
                            opfamilyname, "gin",
                            format_procedure(procform->amproc),
                            procform->amprocnum)));
            result = false;
        }
    }

    /* Check individual operators */
    for (i = 0; i < oprlist->n_members; i++)
    {
        HeapTuple    oprtup = &oprlist->members[i]->tuple;
        Form_pg_amop oprform = (Form_pg_amop) GETSTRUCT(oprtup);

        /* TODO: Check that only allowed strategy numbers exist */
        if (oprform->amopstrategy < 1 || oprform->amopstrategy > 63)
        {
            ereport(INFO,
                    (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                     errmsg("operator family \"%s\" of access method %s contains operator %s with invalid strategy number %d",
                            opfamilyname, "gin",
                            format_operator(oprform->amopopr),
                            oprform->amopstrategy)));
            result = false;
        }

        /* gin doesn't support ORDER BY operators */
        if (oprform->amoppurpose != AMOP_SEARCH ||
            OidIsValid(oprform->amopsortfamily))
        {
            ereport(INFO,
                    (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                     errmsg("operator family \"%s\" of access method %s contains invalid ORDER BY specification for operator %s",
                            opfamilyname, "gin",
                            format_operator(oprform->amopopr))));
            result = false;
        }

        /* Check operator signature --- same for all gin strategies */
        if (!check_amop_signature(oprform->amopopr, BOOLOID,
                                  oprform->amoplefttype,
                                  oprform->amoprighttype))
        {
            ereport(INFO,
                    (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                     errmsg("operator family \"%s\" of access method %s contains operator %s with wrong signature",
                            opfamilyname, "gin",
                            format_operator(oprform->amopopr))));
            result = false;
        }
    }

    /* Now check for inconsistent groups of operators/functions */
    grouplist = identify_opfamily_groups(oprlist, proclist);
    opclassgroup = NULL;
    foreach(lc, grouplist)
    {
        OpFamilyOpFuncGroup *thisgroup = (OpFamilyOpFuncGroup *) lfirst(lc);

        /* Remember the group exactly matching the test opclass */
        if (thisgroup->lefttype == opcintype &&
            thisgroup->righttype == opcintype)
            opclassgroup = thisgroup;

        /*
         * There is not a lot we can do to check the operator sets, since each
         * GIN opclass is more or less a law unto itself, and some contain
         * only operators that are binary-compatible with the opclass datatype
         * (meaning that empty operator sets can be OK).  That case also means
         * that we shouldn't insist on nonempty function sets except for the
         * opclass's own group.
         */
    }

    /* Check that the originally-named opclass is complete */
    for (i = 1; i <= GINNProcs; i++)
    {
        if (opclassgroup &&
            (opclassgroup->functionset & (((uint64) 1) << i)) != 0)
            continue;            /* got it */
        if (i == GIN_COMPARE_PROC || i == GIN_COMPARE_PARTIAL_PROC)
            continue;            /* optional method */
        if (i == GIN_CONSISTENT_PROC || i == GIN_TRICONSISTENT_PROC)
            continue;            /* don't need both, see check below loop */
        ereport(INFO,
                (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                 errmsg("operator class \"%s\" of access method %s is missing support function %d",
                        opclassname, "gin", i)));
        result = false;
    }
    if (!opclassgroup ||
        ((opclassgroup->functionset & (1 << GIN_CONSISTENT_PROC)) == 0 &&
         (opclassgroup->functionset & (1 << GIN_TRICONSISTENT_PROC)) == 0))
    {
        ereport(INFO,
                (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                 errmsg("operator class \"%s\" of access method %s is missing support function %d or %d",
                        opclassname, "gin",
                        GIN_CONSISTENT_PROC, GIN_TRICONSISTENT_PROC)));
        result = false;
    }


    ReleaseCatCacheList(proclist);
    ReleaseCatCacheList(oprlist);
    ReleaseSysCache(familytup);
    ReleaseSysCache(classtup);

    return result;
}
